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Advanced Driver Assistant Systems

KEFO – GAMF Kar Kecskemét, 2011.03.01

Bence CSÁK, PhD




Driver Assistant Systems “Even the Greek ...” reins

Ramses’ war chariot


Driver Assistant Systems “Reins even today ...”


Driver Assistant Systems Driver assistant systems provide: - comfort for the driver - decreased driver load - increased safety to avoid accidents (98% - 2%) Responsibility remains at the driver 100%. The driver must be able to intervene at any time.


Driver Assistant Systems From the Past

• e-starter • electric lighting (instead of • • • • • •

candles) turn signal brake light roof for driver windscreen wiper (manual 1911, pneumatic 1929, electric 1957) transmission-synchronizer ...

Rolls Royce 1936

Trabant 601 1963 6

Driver Assistant Systems Today / Tomorrow • • • • • • • • • • • • • • •

ABS, ASR, DTC, ESP, HSA, EDL (e-difflock), HDC (Hill Descent Control), BAS (Brake Assistant) ADC (Automatic Damper Control), ASC (Automatic Suspension Control) CC, ACC, PEB, ACC+Lidar+Cam, Stop&Go Assistant, AHT ISA (Intelligent speed adaptation), IAP (Intelligent Accelerator Pedal), TSR (Traffic Sign Recognition) Night Vision LDW (Lane Departure Warning), LKS (Lane Keeping System), LCA (Lane Change Assistant) Light Control (high-beam ctrl, swiveling head light, BMW’s pixel light) Brake force dependent brake light, ambient light dependent position lights Alertness Assistant (via eyelid monitoring & face following) , HUD Blind Spot Detection Wiper Control, Tire Monitoring System Automatic parking, Rear-view camera , Park Assistant Navigation System Platooning, Autonomous Driving Car2Car Communication, V2V, Car2Infrastructure Comms 7

ABS, ASR, DTC, EBS, ESP, HSA, EDL, HDC, BA • • • • • • • • • •

ABS: vehicle stability by avoiding blocking wheels ASR: improved traction and stability during acceleration DTC: improved stability on low-µ during engine brake deceleration EBS: electronically controlled brake application for improved braking (strategies: lining wear, CFC, pedal characteristics, ...) ESP: drive stability by making the vehicle neutrally steered by braking ESP+Steering: like ESP but enhanced with steering intervention HSA: hill start aid via brake application till driver releases the clutch EDL: electronic differential control, locks on µ-split HDC: hill descent control, for off-road vehicles BAS: brake assist: a) brake characteristic control, b) pre-fill 8

Trailer Systems: EBS, RSP, ELC EBS (electronic brake system) trailer braking with no delay trailer braking with correct braking force trailer ABS with enhanced performance (asphalt laying function)

RSP (roll stability program) step 1: braking by lateral acceleration tendency step 2: braking by lateral acceleration value step 3: road groove caused trailer swing mitigation by brake application (dumper anti-tilt function)

ELC (electronic leveling control) frame level regulation and adjustment (leveling underway or for loading, ESP help) lift axle operation (to spare tire wear at low loads) traction help (given to tractor by lifting the front most trailer axle) maneuvering help (to lower turn radius by lifting the rearmost trailer axle) 9

Cruise Control, Adaptive Cruise Control

• • •

CC: cruise control to keep a speed set by the driver ACC: adaptive cruise control, like CC but enables to follow the fluctuation of the traffic around (30..200km/h) by using a radar PEB: Predictive Emergency Braking for warnings, collision avoidance, collision mitigation yaw-rate wheel speed

Possible vehicle path

Intervention time

1: warning 2: partial braking + warning 3: full brake 4: impact ? 10

ACC radar in detail

• • • •

76GHz frequency (λ=3.9mm, so no reflector but lens) FMCW – frequency modulated, continuous wave relative velocity ±8° horizontal viewing angle (±2.5° vertical) 200m range (150m tracking)

exclusion of virtual objects

? ? ?




far object results in stronger doppler effect, due to linear freq change


difference frequency

difference frequency

Doppler shift

Doppler shift

moving object results in asymetric doppler effect





difference frequency

difference frequency

fn time

time time relative velocity

relative velocity

relative velocity


d  fp+fn distance

vrel  fp- fn






• ACC radar accompanied by a short range radar • So, stop & go function is possible, but only on highways and main roads.


Why RADAR needs extensions




Urban ACC Hexagon Mirror

1 2 3 4 5 6

DC motor

Laser Diode




Urban ACC: ACC + (Lidar) + Cam Problems: ACC radar can not see sizes and has not enough viewing angle, so it’s not able to conduct stop & go control in complex environment ACC radar can not distinguish between relevant and irrelevant standing objects (channel top vs. standing veh.) ACC radar does not cover the whole surrounding and can’t see pedestrians With added video processing, urban usage is possible


Sensors & Ranges ∞m comms


0.2-1.5 m

short range radar (24GHZ)

0.2-20 m


0-80 m


0.2-150 m

long range radar (77GHz)

1-200 m


Ad-hoc Tempomat Tests • • •

Tests achieved on a former military airfield PC & CV both equipped with AHT CV follows PC using GPS data of both (shared via WLAN) Time-gap control Diagram shows control transients right after cornering


Blind Spot Detection

• •

Commercial vehicle drivers face big blind spots around their vehicle meaning a considerable potential of accidents with severe injuries and damages Ultrasonic sensors can cover these spots and give a warning if necessary 17

Parking Assistant •

• •

The system measures the given parking place by means of ultrasonic sensors as the vehicle passes by. The driver stops and activates the parking maneuver function. The vehicle parks fully automatically. Alternatively the system does the steering job, while the driver controls gas and brake


Wraparound view

Panorama view Based on 4 cameras No blind spot Situation aware views


Parking Assistance


Video processing in vehicles Object Detection by cam Road Sign Recognition • Road Sign Assistance • Speed Limit Assistance

• Intersection Assistance

• RADAR aided • Collision Warning • Pedestrian detection • ACC Full Speed Range • Low Speed Following • Recognition of cut-in traffic

NightVision • high-beam visibility in low beam situations • increased safety

NIR (700..3000nm) vs. MIR & FIR (3000..50000..1000000nm)


Video-based Lane Systems • • •

Lane Departure Warning System Lane Keeping System Lane Change Assistance


Video-based Lane Systems

Processed video in different driving situations

Video conversion


Lane Departure Systems

Audi Side-Assist

rear-view cam 24

Video-based Lane Systems

Lane Keeping & Driver Distraction Monitoring


Attention Assist


Light Systems

Hella VarioX - head light for each drive situation - needs sensing & intelligence

Hella ASIGNIS brake force dependent brake light ambient light dependent navigation lights 27

Light Systems

Digital Micro Mirror BMW (patent 1987 Texas) 28

Head Up Display


Wiper Control • •

The rain sensor senses water drops on the windscreen and sets wiper pace accordingly. In addition measures the ambient light and the light coming from the direction where the driver sees. This information is used for automatic light control.


Tire Pressure Monitoring System • •


Valve mounted pressure and temperature sensors measure these parameters In case of limit override or dangerous tendency, the system warns the driver. Tire pressure has also serious effect on drive economy (fuel consumption & tire wear)

TPMS sensor is on a turning part, so supply and communication is an issue


Going Wireless


When cars communicate with each other and infrastructure

Car-to-car: - Exchange data of local relevance (Âľ, jam, accident, own trajectory, ...) Car-Infrastructure: - GPS navigation - Road related information (Âľ, slippery road, traffic signs, traffic density, pump station - Aid for systems: shift, ESP, damper ctrl, ... - Internet, Infotainment

Navi-based shifting


Communicating Cars


Car-to-Car Using Multi-hop Messages


Car to Infrastructure / Infrastructure to Car


Platooning & Autonomous Driving

Requirements - Vehicles sense each other - Vehicles communicate with each other - Vehicles sense their position (locally & globally) - Vehicles are capable of autonomous driving Benefits - Commercial vehicle can do more hours on road with no additional driver - Usage of dedicated, extreme narrow lanes - Denser traffic - Less drag


Platooning – Drag Benefit

1m 50% smaller air drag/unit compared to a single vehicle

30% reduced air drag compared to 1L

0,25 L 14% reduced airdrag compared to 1L situation



Trends Sensor-based recognition of the surrounding traffic situation increases (radar, cam, lidar, vibration, ...) More complete traffic situation recognition (sensor fusion, more computing power) DAS

More optimal distribution of driving tasks between driver and DAS Widening of HMI via sound, speech generation, speech recognition, haptic (seat, steering wheel, pedals) Cost reduction via new technologies (navi, tpms, autoshift, no crash, ...) Better vehicle control via cooperative systems (steer+brake EBS) Increasing communication with infrastructure Increasing communication with other vehicles System complexity increases. The goal is to create the accident free vehicle, which can cope with dense traffic and can decrease driver’s load. Driver assistant systems turn to safety systems by the time. 39


Dr. Bence CSĂ K KNORR-BREMSE R&D Center Budapest H-1119, Budapest, Major u. 69. Phone: +36 1 3829-979 Fax: +36 1 3829 810 mailto: 40

Advanced Driver Assistant Systems